Hi all,

Write a procedure rsum that sums the reciprocals of the elements of a list.  So rsum( [a,b,c] ) should return 1/a + 1/b + 1/c.

How would i modify my code so that it does this... I know theres a much simpler way (rsum := L -> add( 1/x, x in L ):) but i would like to know how to edit the one ive done.

Heres my code so far...

rsum := proc(L)
local n;
    for n in L do
      1/n
    end do;
end proc;

 

I would lke to know how I can make multiple 2-d pointplots; the pointplot only seems to work for one plot, but I could be wrong... . Tony Lawrance

 

Is there any command to find an tangent for a fuction in maple. My example here is f(x,y) = x- x - y + y and graphing the function and it's tangent at plane (1,1).

Recently, Robert I helped me with a question: To approximate f(x,y) = y/ xby a polynomial of degree 6 in x -1 and y + 1. He said answer to this is achieved by following: mtaylor (y / x, [x=1,y=-1],7);         If this is correct, what does the 7 do?

 

is it possible to extract a coordinate from a graph?

ie. i want to know the maximum/minumum by just havin the graph

cuz for some reason the max/min commands arent working

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hi, i need help with finding minimum near the end

cant seem to find an operation in doing so

really need some help and assistance

 

Hi
is possible to save the dsolve results for a numerical integration? so that i can reload them with out re-run the integrator.
 

hi, i am trying to find a minimal value for an expression

orginally the expression comprised of two variables t and a

after taking a definite integral from t=0..t=1, the expression should only contain a

and using the commands, i found:

2 question

one, how do you plot two graphs together of f(x,y)= x - x - y + y and it's tanget at plane (1,1). i can do it individually but is it just simple as putting them in one notation in plot command?  for f(x,y) i used plot3d(f(x,y)) from -pi to pi for both x and y but don't know how to put tangent in at plane (1,1)

two, how apporoximate f(x,y) = y / x by a polynomial of degree 6 in x-1 and y+1.

any hints or examples  are much appreciated.

thx

Hey guys, I want to plot a differential equation (I'm looking for something a 2d direction field plot) The differential equation is a composition of piecewise functions and a cubic spline. I have to use the subs() call to convert the function h(t) into a numeric (i dont really understand this part but was told to do this). Anyways I need the DEplot error explained to me. Here I show all of the relavent code leading up to the error: with(CurveFitting): with(DEtools): z := t -> 4.713*sin((1/22356)*Pi*t)+.743*sin((1/21600)*Pi*t)+.964*sin((1/22788)*Pi*t)

does any one know if it is possible to solve numerically a ODE sys write in matrix form without first evaluate is as a set of equation?

for example my system is y'(x)=A(x,y).b(x,y)
where y'(x) and b(x,y) are Vectors and A(x,y) is a matrix

so i would solve it numerically without doing first the dotproduct symbolically. I woud do this because my system equation is constitudet not from a simple matrix.vector but by large matrix inversion so do it symbolically first take a lot of time and memory.

When I do an integral Maple sometimes spits out ridiculous answers.... I don't have an example off hand but oft it will give me trig functions that it SHOULD evaluate. Last night at my lab I was trying to do a taylor series that involved sine squared and to the fourth, and instead of giving me NUMBERS like I needed it left it in terms of sine which was utterly useless to me!

How can I assign an argument to the real numbers in an interval?

I have a matrix M which is 3x4.  I need add a fourth row to it.  I've been trying

 

E:=Matrix([ [M], [0,0,0,1] ])

and

E:=Matrix([ [Row(M,1)], [Row(M,2)], [Row(M,3)], [0,0,0,1] ])

But neither of them worked.  How would I do this?

Thanks,
Dave

Hi, I am trying to find a general solution for a special case of the 4x4 Riccati Equation. My worksheet chugs for 5 hours and 2gigs of memory before crashing. Am I posing the problem incorrectly? Or will more memory help (and if so, how much memory)? > with(LinearAlgebra); > A := Matrix([[ZeroMatrix(2), IdentityMatrix(2)], [ZeroMatrix(2), Matrix(2, symbol = a)]]); > B := Matrix([[ZeroMatrix(2)], [Matrix(2, symbol = b)]]);